Controlling linphone

I am working on controlling linphone from the outside, via its command-line interface. To make this work perfectly, I had to modify the code of linphonec slightly to force it to flush after every line, otherwise, Linux is too smart and knows that the stdin/out are pipes and does some additional buffering. There are probably better ways to do this though.

ALSA Problems after Feisty Update

I started to get the following problems when running linphone on top of ALSA after my Feisty update.

ALSA lib confmisc.c:1105:(snd_func_refer) Unable to find definition 'defaults.pcm.dmix_format'
ALSA lib conf.c:3500:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:3957:(snd_config_expand) Args evaluate error: No such file or directory
ALSA lib pcm.c:2145:(snd_pcm_open_noupdate) Unknown PCM dmix:Intel

I thought linphone was the problem, but this had to do with old ALSA configuration files lying around. Removing (or moving) the .asoundrc and .asoundrc.asoundconf files in your home directory, as explained here will do the trick.

Fixing TV Card and WebCam culpirts.

A number of software packages, including OpenWengo or linphone, will usually insist on using /dev/video0 as the device from which they acquire pictures. This might turn into a problem if your hardware also has a PCI based TV card. Indeed, the TV card would then automatically turn into video0 while the webcam will be video1, a behaviour that you do not which to have.

The solution is a mixture of this tutorial and this blog entry. What I did was finding out the vendor/product of the webcam via lsusb and finding the vendor and device of the TV card via udevinfo -a -p /sys/class/video4linux/video0. I ended up with the following content for a (new) file called 35-perso.rules in /etc/udev/rules.d/:

KERNEL=="video[0-9]*", SYSFS{idVendor}=="046d", SYSFS{idProduct}=="08ad", BUS=="usb", NAME="v4l/video0", SYMLINK="video0"
KERNEL=="video[0-9]*", SYSFS{vendor}=="0x1131", SYSFS{device}=="0x7134", BUS=="pci", NAME="v4l/video1", SYMLINK="video1"

Note that the NAME directive is mandatory for this to work properly, otherwise you'll still have video1 and video0 crossed.

USB-UIRT on Ubuntu

Installing an USB-UIRT device on an Ubuntu system is as simple as explained on the community web site. Automating this would require to automate the dmesg lookup part (or to force the user to use a given USB port?).

However, even though it seems that simple on Ubuntu, it seems that the device is not properly recognised so far. I have been able to make it work on Windows using IRCommand2, but could probably have been using this solution, i.e. the lrnhelper and uutx applications.

However, it is possible to do this on Linux, misterhouse does it. Pay specific attention to the note about using "udev" to fix the name of the USB-UIRT device in the OS to avoid dynamic allocation and the problem described above.